obedience vs tractability

obedience

noun
  • The quality of being obedient. 

  • The collective body of persons subject to any particular authority. 

  • A written instruction from the superior of an order to those under him. 

  • Any official position under an abbot's jurisdiction. 

tractability

noun
  • The state of being tractable or docile; docility; tractableness. 

How often have the words obedience and tractability occurred in a corpus of books? (source: Google Ngram Viewer )